Polycarbonate-polysiloxane copolymer compositions, articles formed therefrom, and methods of manufacture thereof

ABSTRACT

A polycarbonate composition comprises: a first poly(carbonate-siloxane) copolymer comprising carbonate units and siloxane units, wherein less than 0.5 mol % of the siloxane units are directly coupled to another siloxane unit; the first poly(carbonate-siloxane) copolymer comprising siloxane units with an average block length of about 10 to about 100, and a siloxane content from 5 wt % to 8 wt %; a second poly(carbonate-siloxane) copolymer comprising carbonate units and siloxane units, wherein less than 0.5 mol % of the siloxane units are directly coupled to another siloxane unit; the second poly(carbonate-siloxane) copolymer comprising siloxane units with an average block length of 10 to 100, a siloxane content from 10 wt % to 30 wt %, and wherein the weight ratio of the first poly(carbonate-siloxane) copolymer to the second poly(carbonate-siloxane) copolymer is 2 to 20; and optionally a bisphenol polycarbonate; wherein the polycarbonate composition has a total siloxane content of 2.5 wt % to 10 wt % and a molded part of 1 mm thickness has a haze of less than 2% as measured by HazeGard (ASTM D1003-00).

BACKGROUND

This disclosure relates to polycarbonate compositions, articles formedtherefrom, and their methods of manufacture, and in particular topolycarbonate-polysiloxane copolymer compositions with advantageousproperties such as improved aesthetic properties, good impact, ordesirable chemical resistance.

Polycarbonate homopolymers and polycarbonate copolymers are useful in awide variety of applications at least in part because of their goodbalance of properties, such as moldability, heat resistance and impactproperties, among others. Despite extensive research on these materialsover the years, there still remains a need in the art for improvedpolycarbonate compositions that meet increasingly stringent industrystandards.

For example, polycarbonate-polysiloxane copolymers can have goodmechanical properties and low temperature impact resistance. However,blends of a polycarbonate homopolymer with such apolycarbonate-polysiloxane can result in poor aesthetics of moldedparts. Aesthetic defects can include excess haze, limited color spacecapability, pearlescence, or other surface defects related to moldingsuch as streaks and flow lines. To improve the aesthetics, otherdesirable properties such as low temperature impact and chemicalresistance may be comprised. There accordingly remains a need in the artfor polycarbonate compositions that can have balanced aesthetics, lowtemperature impact, and chemical resistance.

SUMMARY

A polycarbonate composition comprises: a first poly(carbonate-siloxane)copolymer comprising carbonate units and siloxane units, wherein lessthan 0.5 mol % of the siloxane units are directly coupled to anothersiloxane unit; the first poly(carbonate-siloxane) copolymer comprisingsiloxane units with an average block length of about 10 to about 100,and a siloxane content from 5 wt % to 8 wt % based on the total weightof the first poly(carbonate-siloxane) copolymer; a secondpoly(carbonate-siloxane) copolymer comprising carbonate units andsiloxane units, wherein less than 0.5 mol % of the siloxane units aredirectly coupled to another siloxane unit; the secondpoly(carbonate-siloxane) copolymer comprising siloxane units with anaverage block length of 10 to 100, a siloxane content from 10 wt % to 30wt % based on the total weight of the second poly(carbonate-siloxane)copolymer, and wherein the weight ratio of the firstpoly(carbonate-siloxane) copolymer to the secondpoly(carbonate-siloxane) copolymer is 2 to 20; and optionally abisphenol polycarbonate different from the firstpoly(carbonate-siloxane) copolymer and the secondpoly(carbonate-siloxane) copolymer; wherein the polycarbonatecomposition has a total siloxane content of 2.5 wt % to 10 wt % based onthe total weight of the composition and a molded part of 1 mm thicknesshas a haze of less than 2% as measured by HazeGard (ASTM D1003-00).

In another embodiment, an article selected from a molded article, athermoformed article, an extruded film, an extruded sheet, a honeycombstructure, one or more layers of a multi-layer article, a substrate fora coated article, and a substrate for a metallized article comprises theabove-described polycarbonate composition.

In yet another embodiment, a method of manufacture of an articlecomprises molding, extruding, casting, or shaping the above-describedpolycarbonate composition into an article.

The above described and other features are exemplified by the followingDrawings, Detailed Description, and Examples.

DETAILED DESCRIPTION

The inventors hereof have discovered that polycarbonate compositionshaving a balanced impact, chemical resistance, and aesthetic propertiescan be obtained by combining at least two poly(carbonate-siloxane)copolymers and an optional bisphenol polycarbonate different from thefirst and second poly(carbonate-siloxane) copolymers, wherein the firstpoly(carbonate-siloxane) copolymer has a siloxane content of 5 wt % to 8wt % based on the total weight of the first poly(carbonate-siloxane)copolymer, and the second poly(carbonate-siloxane) copolymer has asiloxane content of 10 wt % to 30 wt % based on the total weight of thesecond poly(carbonate-siloxane) copolymer; and further wherein in boththe first and second poly(carbonate-siloxane) copolymers, less than 0.5mol % of the siloxane units are directly coupled to another siloxaneunit. Compared to the sample of a reference composition containing thesame first poly(carbonate-siloxane) copolymer but a secondpoly(carbonate-siloxane) copolymer having greater than 10 mol % ofsiloxane units directly coupled to another siloxane unit, at the sametotal siloxane loading level, a sample of the compositions of thedisclosure has reduced haziness, which is typically indicating areduction in aesthetic defects, such as black streaking, knitlinevisibility, gate blush, or pearlescence. The compositions of thedisclosure also have similar or improved impact and chemical resistancecompared to the reference composition.

The individual components of the compositions are described in moredetail below.

The polycarbonate compositions comprise at least twopolycarbonate-polysiloxane copolymers, also referred to as apoly(carbonate-siloxane)s. The poly(carbonate-siloxane)s comprisecarbonate units and siloxane units. The carbonate units are bisphenolcarbonate units of the formula (2)

wherein R^(a) and R^(b) are each independently C₁₋₁₂ alkyl, C₁₋₁₂alkenyl, C₃₋₈ cycloalkyl, or C₁₋₁₂ alkoxy, p and q are eachindependently 0 to 4, and X^(a) is a single bond, —O—, —S—, —S(O)—,—S(O)₂—, —C(O)—, a C₁₋₁₁ alkylidene of formula —C(R^(c))(R^(d))— whereinR^(c) and R^(d) are each independently hydrogen or C₁₋₁₀ alkyl, or agroup of the formula —C(═R^(e))— wherein R^(e) is a divalent C₁₋₁₀hydrocarbon group

The carbonate units can be derived from a dihydroxy compound such as abisphenol of formula (3).

In formula (3), R^(a), R^(b), X^(a), p, and q are the same as thosedefined in the context of formula (2).

Examples of bisphenol compounds include 4,4′-dihydroxybiphenyl,1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene,bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane,bis(4-hydroxyphenyl)-1-naphthylmethane, 1,2-bis(4-hydroxyphenyl)ethane,1,1-bis(4-hydroxyphenyl)-1-phenylethane,2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane,bis(4-hydroxyphenyl)phenylmethane,2,2-bis(4-hydroxy-3-bromophenyl)propane, 1,1-bis(hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane,1,1-bis(4-hydroxyphenyl)isobutene,1,1-bis(4-hydroxyphenyl)cyclododecane,trans-2,3-bis(4-hydroxyphenyl)-2-butene,2,2-bis(4-hydroxyphenyl)adamantane,alpha,alpha′-bis(4-hydroxyphenyl)toluene,bis(4-hydroxyphenyl)acetonitrile,2,2-bis(3-methyl-4-hydroxyphenyl)propane,2,2-bis(3-ethyl-4-hydroxyphenyl)propane,2,2-bis(3-n-propyl-4-hydroxyphenyl)propane,2,2-bis(3-isopropyl-4-hydroxyphenyl)propane,2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane,2,2-bis(3-t-butyl-4-hydroxyphenyl)propane,2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane,2,2-bis(3-allyl-4-hydroxyphenyl)propane,2,2-bis(3-methoxy-4-hydroxyphenyl)propane,2,2-bis(4-hydroxyphenyl)hexafluoropropane,1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene,1,1-dibromo-2,2-bis(4-hydroxyphenyl)ethylene,1,1-dichloro-2,2-bis(5-phenoxy-4-hydroxyphenyl)ethylene,4,4′-dihydroxybenzophenone, 3,3-bis(4-hydroxyphenyl)-2-butanone,1,6-bis(4-hydroxyphenyl)-1,6-hexanedione, ethylene glycolbis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)ether,bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide,bis(4-hydroxyphenyl)sulfone, 9,9-bis(4-hydroxyphenyl)fluorene,2,7-dihydroxypyrene,6,6′-dihydroxy-3,3,3′,3′-tetramethylspiro(bis)indane (“spirobiindanebisphenol”), 3,3-bis(4-hydroxyphenyl)phthalimide,2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxythianthrene,2,7-dihydroxyphenoxathin, 2,7-dihydroxy-9,10-dimethylphenazine,3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, and2,7-dihydroxycarbazole; resorcinol, substituted resorcinol compoundssuch as 5-methyl resorcinol, 5-ethyl resorcinol, 5-propyl resorcinol,5-butyl resorcinol, 5-t-butyl resorcinol, 5-phenyl resorcinol, 5-cumylresorcinol, 2,4,5,6-tetrafluoro resorcinol, 2,4,5,6-tetrabromoresorcinol, or the like; catechol; hydroquinone; substitutedhydroquinones such as 2-methyl hydroquinone, 2-ethyl hydroquinone,2-propyl hydroquinone, 2-butyl hydroquinone, 2-t-butyl hydroquinone,2-phenyl hydroquinone, 2-cumyl hydroquinone, 2,3,5,6-tetramethylhydroquinone, 2,3,5,6-tetra-t-butyl hydroquinone, 2,3,5,6-tetrafluorohydroquinone, 2,3,5,6-tetrabromo hydroquinone, or the like.

Specific dihydroxy compounds include 2,2-bis(4-hydroxyphenyl) propane(“bisphenol A” or “BPA”), 3,3-bis(4-hydroxyphenyl) phthalimidine,2-phenyl-3,3′-bis(4-hydroxyphenyl) phthalimidine (also known as N-phenylphenolphthalein bisphenol, “PPPBP”, or3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-1-one),1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, and1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (isophoronebisphenol).

The siloxane units (also referred to as polysiloxane blocks) are offormula (4)

wherein each R is independently a C₁₋₁₃ monovalent organic group. Forexample, R can be a C₁-C₁₃ alkyl, C₁-C₁₃ alkoxy, C₂-C₁₃ alkenyl, C₂-C₁₃alkenyloxy, C₃-C₆ cycloalkyl, C₃-C₆ cycloalkoxy, C₆-C₁₄ aryl, C₆-C₁₀aryloxy, C₇-C₁₃ arylalkyl, C₇-C₁₃ aralkoxy, C₇-C₁₃ alkylaryl, or C₇-C₁₃alkylaryloxy. The foregoing groups can be fully or partially halogenatedwith fluorine, chlorine, bromine, or iodine, or a combination thereof.In an embodiment, where a transparent polycarbonate-polysiloxane isdesired, R is unsubstituted by halogen. Combinations of the foregoing Rgroups can be used in the same copolymer.

The value of E in formula (4) can vary widely depending on the type andrelative amount of each component in the polycarbonate composition, thedesired properties of the composition, and like considerations.Generally, E has an average value of 10 to 100, preferably 20 to 60,more preferably 30 to 50.

In an embodiment, the siloxane units are of formula (5)

wherein E is as defined above in the context of formula (4); each R canbe the same or different, and is as defined above in the context offormula (4); and Ar can be the same or different, and is a substitutedor unsubstituted C₆-C₃₀ arylene, wherein the bonds are directlyconnected to an aromatic moiety. Ar groups in formula (5) can be derivedfrom a C₆-C₃₀ dihydroxyarylene compound, for example a dihydroxycompound of formula (3). Exemplary dihydroxyarylene compounds are1,1-bis(4-hydroxyphenyl) methane, 1,1-bis(4-hydroxyphenyl) ethane,2,2-bis(4-hydroxyphenyl) propane, 2,2-bis(4-hydroxyphenyl) butane,2,2-bis(4-hydroxyphenyl) octane, 1,1-bis(4-hydroxyphenyl) propane,1,1-bis(4-hydroxyphenyl) n-butane, 2,2-bis(4-hydroxy-1-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl) cyclohexane, bis(4-hydroxyphenylsulfide), and 1,1-bis(4-hydroxy-t-butylphenyl) propane. Combinationscomprising at least one of the foregoing dihydroxy compounds can also beused.

Specific examples of siloxane units of formula (5) include those of theformulas (5a) and (5b):

In another embodiment, the siloxane units are of formula (6)

wherein R and E are as described above in the context of formula (4),and each R⁵ is independently a divalent C₁-C₃₀ organic group, andwherein the polymerized polysiloxane unit is the reaction residue of itscorresponding dihydroxy compound. In a specific embodiment, thepolydiorganosiloxane blocks are of formula (7):

wherein R and E are as defined above in the context of formula (4). R⁶in formula (7) is a divalent C₂-C₈ aliphatic. Each M in formula (7) canbe the same or different, and can be a halogen, cyano, nitro, C₁-C₈alkylthio, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₂-C₈ alkenyl, C₂-C₈ alkenyloxy,C₃-C₈ cycloalkyl, C₃-C₈ cycloalkoxy, C₆-C₁₀ aryl, C₆-C₁₀ aryloxy, C₇-C₁₂aralkyl, C₇-C₁₂ aralkoxy, C₇-C₁₂ alkylaryl, or C₇-C₁₂ alkylaryloxy,wherein each n is independently 0, 1, 2, 3, or 4.

In an embodiment, M is bromo or chloro, an alkyl such as methyl, ethyl,or propyl, an alkoxy such as methoxy, ethoxy, or propoxy, or an arylsuch as phenyl, chlorophenyl, or tolyl; R⁶ is a dimethylene,trimethylene or tetramethylene; and R is a C₁₋₈ alkyl, haloalkyl such astrifluoropropyl, cyanoalkyl, or aryl such as phenyl, chlorophenyl ortolyl. In another embodiment, R is methyl, or a combination of methyland trifluoropropyl, or a combination of methyl and phenyl. In stillanother embodiment, R is methyl, M is methoxy, n is one, R⁶ is adivalent C₁-C₃ aliphatic group. Specific polydiorganosiloxane blocks areof the formula

or a combination comprising at least one of the foregoing, wherein E hasan average value of 10 to 100, preferably 20 to 60, more preferably 30to 50, or 40 to 50.

Blocks of formula (7) can be derived from the corresponding dihydroxypolydiorganosiloxane of formula (8),

which in turn can be prepared effecting a platinum-catalyzed additionbetween the siloxane hydride and an aliphatically unsaturated monohydricphenol such as eugenol, 2-alkylphenol, 4-allyl-2-methylphenol,4-allyl-2-phenylphenol, 4-allyl-2-bromophenol, 4-allyl-2-t-butoxyphenol,4-phenyl-2-phenylphenol, 2-methyl-4-propylphenol,2-allyl-4,6-dimethylphenol, 2-allyl-4-bromo-6-methylphenol,2-allyl-6-methoxy-4-methylphenol and 2-allyl-4,6-dimethylphenol.

The polycarbonate-polysiloxane copolymers can then be manufactured usingone or more of the tube reactor processes described in U.S. PatentApplication Publication No. 2004/0039145, or the process described inU.S. Pat. No. 6,723,864, or the process described in U.S. Pat. No.8,466,249.

In an embodiment, the polycarbonate-polysiloxane copolymers comprisecarbonate units derived from bisphenol A, and repeating siloxane units(5a), (5b), (7a), (7b), (7c), or a combination comprising at least oneof the foregoing (specifically of formula 7a), wherein E has an averagevalue of E has an average value of 10 to 100, preferably 20 to 60, morepreferably 30 to 50 or 40 to 50.

The first polycarbonate-polysiloxane copolymer has a siloxane content of5 wt % to 8 wt %, specifically 5 wt % to 7 wt %, based on the totalweight of the first polycarbonate-polysiloxane copolymer. As usedherein, “siloxane content” of a poly(carbonate-siloxane) copolymerrefers to the content of siloxane units based on the total weight of thepolysiloxane-polycarbonate copolymer. The firstpolyorganosiloxane-polycarbonate copolymer can have a weight averagemolecular weight of 18,000 to 25,000 Daltons, specifically 20,000 to22,000 Daltons as measured by gel permeation chromatography using acrosslinked styrene-divinyl benzene column, at a sample concentration of1 milligram per milliliter, and as calibrated with polycarbonatestandards.

Generally, a polycarbonate-polysiloxane block copolymer can beconsidered as being formed from a bisphenol of Formula (3) and adihydroxy polydiorganosiloxane of formula (8), with carbonate linkagesbetween these monomers. There are potentially three types of linkagesbetween the carbonate blocks (C) and siloxane blocks (S). Illustrativelythese linkages are C—C, S—S, and C—S. In an embodiment, in the firstpolysiloxane-polycarbonate, less than 0.5 mol % of the siloxane unitsare directly coupled to another siloxane units, specifically less than0.2 mol % of the siloxane units are directly coupled to another siloxaneunits, more specifically less than 0.1 mol % of the siloxane units aredirectly coupled to another siloxane units.

The second polycarbonate-polysiloxane copolymer has a siloxane contentof 10 wt % to 30 wt %, specifically 15 wt % to 25 wt %, morespecifically 18 to 22, each based on the total weight of the secondpolycarbonate-polysiloxane copolymer. The secondpolyorganosiloxane-polycarbonate copolymer can have a weight averagemolecular weight of 18,000 to 25,000 Daltons, specifically 20,000 to22,000 Daltons as measured by gel permeation chromatography using acrosslinked styrene-divinyl benzene column, at a sample concentration of1 milligram per milliliter, and as calibrated with polycarbonatestandards.

The inventors hereof have found that the in order to provide apolycarbonate composition having balanced impact, chemical resistance,and aesthetics, the type of linkages between the carbonate units and thesiloxane units in the second polycarbonate-polysiloxane copolymersshould be controlled. In the second polysiloxane-polycarbonate, lessthan 0.5 mol % of the siloxane units are directly coupled to anothersiloxane units, specifically less than 0.2 mol % of the siloxane unitsare directly coupled to another siloxane units, more specifically lessthan 0.1 mol % of the siloxane units are directly coupled to anothersiloxane units.

In an embodiment, the weight ratio of the firstpolycarbonate-polysiloxane copolymer to the secondpolycarbonate-polysiloxane copolymer is 2 to 20, specifically 2 to 15,more specifically 5 to 15. The polycarbonate compositions can have atotal siloxane content of 2.5 wt % to 10 wt %, specifically 3 wt % to 9wt %, more specifically 3.5 wt % to 8.5 wt %, each based on the totalweight of the polycarbonate compositions.

The polycarbonate compositions can also comprise a bisphenolpolycarbonate different from the first poly(carbonate-siloxane)copolymer and the second poly(carbonate-siloxane) copolymer. Thebisphenol polycarbonate comprises carbonate units of formula (2).Preferably the bisphenol polycarbonate is a bisphenol A polycarbonatehomopolymer, also referred to as bisphenol A homopolycarbonate, whichhas repeating structural carbonate units of the formula (1)

Polycarbonate can be manufactured by processes such as interfacialpolymerization and melt polymerization, which are known, and aredescribed, for example, in WO 2013/175448 A1 and WO 2014/072923 A1. Anend-capping agent (also referred to as a chain stopper agent or chainterminating agent) can be included during polymerization to provide endgroups, for example monocyclic phenols such as phenol, p-cyanophenol,and C₁-C₂₂ alkyl-substituted phenols such as p-cumyl-phenol, resorcinolmonobenzoate, and p- and tertiary-butyl phenol, monoethers of diphenols,such as p-methoxyphenol, monoesters of diphenols such as resorcinolmonobenzoate, functionalized chlorides of aliphatic monocarboxylic acidssuch as acryloyl chloride and methacryoyl chloride, andmono-chloroformates such as phenyl chloroformate, alkyl-substitutedphenyl chloroformates, p-cumyl phenyl chloro formate, and toluene chloroformate. Phenol and para-cumylphenol are specifically mentioned.Combinations of different end groups can be used. Branched polycarbonateblocks can be prepared by adding a branching agent duringpolymerization, for example trimellitic acid, trimellitic anhydride,trimellitic trichloride, tris-p-hydroxyphenylethane, isatin-bis-phenol,tris-phenol TC (1,3,5-tris((p-hydroxyphenyl)isopropyl)benzene),tris-phenol PA (4(4(1,1-bis(p-hydroxyphenyl)-ethyl) alpha,alpha-dimethyl benzyl)phenol), 4-chloroformyl phthalic anhydride,trimesic acid, and benzophenone tetracarboxylic acid. The branchingagents can be added at a level of 0.05 to 2.0 wt. %. Combinationscomprising linear polycarbonates and branched polycarbonates can beused.

In an embodiment, the bisphenol polycarbonate is a linear bisphenol Apolycarbonate homopolymer having a weight average molecular weight of10,000 to 100,000 Daltons, specifically 15,000 to 50,000 Daltons, morespecifically 17,000 to 35,000 Daltons, as measured by gel permeationchromatography (GPC), using a crosslinked styrene-divinylbenzene columnand calibrated to polycarbonate references. GPC samples are prepared ata concentration of 1 mg per ml, and are eluted at a flow rate of 1.5 mlper minute.

More than one bisphenol A polycarbonate homopolymer can be present. Forexample, the polycarbonate compositions can comprise a first bisphenol Apolycarbonate homopolymer having a weight average molecular weight of20,000 Daltons to 25,000 Daltons or 20,000 Daltons to 23,000 Daltons or20,000 Daltons to 22,000 Daltons as measured by GPC using BPApolycarbonate standards and a second bisphenol A polycarbonatehomopolymer having a weight average molecular weight of 28,000 to 32,000Daltons, or a second bisphenol A polycarbonate homopolymer having aweight average molecular weight of 16,000 Daltons to 19,000 Daltons,each measured by GPC using BPA polycarbonate standards. The weight ratioof the first bisphenol A polycarbonate homopolymer relative to thesecond bisphenol A polycarbonate homopolymer is 10:1 to 1:10,specifically 5:1 to 1:5, more specifically 3:1 to 1:3 or 2:1 to 1:2. Inan embodiment, the polycarbonate composition comprises 0 wt % to 69 wt %or 15 wt % to 62 wt % of one or more bisphenol polycarbonates differentfrom the first and second poly(carbonate-siloxane).

In addition to the first and second poly(carbonate-siloxane)s and thebisphenol polycarbonate different from the first and secondpoly(carbonate-siloxane), the polycarbonate composition can optionallyinclude various additives ordinarily incorporated into polymercompositions of this type, with the proviso that the additive(s) areselected so as to not significantly adversely affect the desiredproperties of the polycarbonate composition, in particular impact,chemical resistance, and aesthetics. Additives include fillers,reinforcing agents, antioxidants, heat stabilizers, light stabilizers,ultraviolet (UV) light stabilizers, plasticizers, lubricants, moldrelease agents, antistatic agents, colorants such as such as titaniumdioxide, carbon black, and organic dyes, surface effect additives,radiation stabilizers, flame retardants, and anti-drip agents. Acombination of additives can be used, for example a combination of aheat stabilizer, mold release agent, and ultraviolet light stabilizer.In general, the additives are used in the amounts generally known to beeffective. For example, the total amount of the additives (other thanany impact modifier, filler, or reinforcing agents) can be 0.01 to 5 wt.%, based on the total weight of the polycarbonate composition. In anembodiment, the polycarbonate composition comprises no more than 5 wt. %based on the weight of the composition of a processing aid, a heatstabilizer, an antioxidant, an ultra violet light absorber, or acombination comprising at least one of the foregoing.

The polycarbonate compositions can optionally include a colorantcomposition containing pigment and/or dye additives. Useful pigments caninclude, for example, inorganic pigments such as metal oxides and mixedmetal oxides such as zinc oxide, titanium dioxides, iron oxides, or thelike; sulfides such as zinc sulfides, or the like; aluminates; sodiumsulfo-silicates sulfates, chromates, or the like; carbon blacks; zincferrites; ultramarine blue; organic pigments such as azos, di-azos,quinacridones, perylenes, naphthalene tetracarboxylic acids,flavanthrones, isoindolinones, tetrachloroisoindolinones,anthraquinones, enthrones, dioxazines, phthalocyanines, and azo lakes;Pigment Red 101, Pigment Red 122, Pigment Red 149, Pigment Red 177,Pigment Red 179, Pigment Red 202, Pigment Violet 29, Pigment Blue 15,Pigment Blue 60, Pigment Green 7, Pigment Yellow 119, Pigment Yellow147, Pigment Yellow 150, and Pigment Brown 24; or combinationscomprising at least one of the foregoing pigments.

Dyes are generally organic materials and include coumarin dyes such ascoumarin 460 (blue), coumarin 6 (green), nile red or the like;lanthanide complexes; hydrocarbon and substituted hydrocarbon dyes;polycyclic aromatic hydrocarbon dyes; scintillation dyes such as oxazoleor oxadiazole dyes; aryl- or heteroaryl-substituted poly (C₂₋₈) olefindyes; carbocyanine dyes; indanthrone dyes; phthalocyanine dyes; oxazinedyes; carbostyryl dyes; napthalenetetracarboxylic acid dyes; porphyrindyes; bis(styryl)biphenyl dyes; acridine dyes; anthraquinone dyes;cyanine dyes; methine dyes; arylmethane dyes; azo dyes; indigoid dyes,thioindigoid dyes, diazonium dyes; nitro dyes; quinone imine dyes;aminoketone dyes; tetrazolium dyes; thiazole dyes; perylene dyes,perinone dyes; bis-benzoxazolylthiophene (BBOT); triarylmethane dyes;xanthene dyes; thioxanthene dyes; naphthalimide dyes; lactone dyes;fluorophores such as anti-stokes shift dyes which absorb in the nearinfrared wavelength and emit in the visible wavelength, or the like;luminescent dyes such as 7-amino-4-methylcoumarin;3-(2′-benzothiazolyl)-7-diethylaminocoumarin;2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole;2,5-bis-(4-biphenylyl)-oxazole; 2,2′-dimethyl-p-quaterphenyl;2,2-dimethyl-p-terphenyl; 3,5,3″″,5″″-tetra-t-butyl-p-quinquephenyl;2,5-diphenylfuran; 2,5-diphenyloxazole; 4,4′-diphenylstilbene;4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran;1,1′-diethyl-2,2′-carbocyanine iodide;3,3′-diethyl-4,4′,5,5′-dibenzothiatricarbocyanine iodide;7-dimethylamino-1-methyl-4-methoxy-8-azaquinolone-2;7-dimethylamino-4-methylquinolone-2;2-(4-(4-dimethylaminophenyl)-1,3-butadienyl)-3-ethylbenzothiazoliumperchlorate; 3-diethylamino-7-diethyliminophenoxazonium perchlorate;2-(1-naphthyl)-5-phenyloxazole; 2,2′-p-phenylen-bis(5-phenyloxazole);rhodamine 700; rhodamine 800; pyrene, chrysene, rubrene, coronene, orthe like; or combinations comprising at least one of the foregoing dyes.

The composition can have any suitable color including white, gray, lightgray, black, and the like. The white or light gray color can exhibit anL* value greater than or equal to 80. A composition having a white orlight gray color can comprise an amount of titanium dioxide in amountsof 0.1 to 30 wt. %, 0.1 to 25 wt. %, 0.1 to 20 wt. %, or 0.1 to 15 wt.%, each based on the total weight of the polycarbonate composition.

The gray or black color can exhibit an L* value of below 80. Acomposition having a gray or black color can comprise an amount ofcarbon black of greater than zero and less than 1.5 wt. % based on thetotal weight of the colorant composition. In an embodiment, a moldedsample having a thickness of 1 mm formed from the composition has anaverage L* value of 29 or less as measure by the CIE Lab method, 10degree observer, D65 illuminant, specular component included, measuredin reflectance mode.

The polycarbonate compositions may optionally include flame retardants.Various types of flame retardants can be utilized. In one embodiment,the flame retardant additives include, for example, flame retardantsalts such as alkali metal salts of perfluorinated C₁-C₁₆ alkylsulfonates such as potassium perfluorobutane sulfonate (Rimar salt),potassium perfluoroctane sulfonate, tetraethylammonium perfluorohexanesulfonate, potassium diphenylsulfone sulfonate (KSS), and the like,sodium benzene sulfonate, sodium toluene sulfonate (NATS) and the like;and salts formed by reacting for example an alkali metal or alkalineearth metal (for example lithium, sodium, potassium, magnesium, calciumand barium salts) and an inorganic acid complex salt, for example, anoxo-anion, such as alkali metal and alkaline-earth metal salts ofcarbonic acid, such as Na₂CO₃, K₂CO₃, MgCO₃, CaCO₃, and BaCO₃ orfluoro-anion complex such as Li₃AlF₆, BaSiF₆, KBF₄, K₃AlF₆, KAlF₄,K₂SiF₆, and/or Na₃AlF₆ or the like. Rimar salt and KSS and NATS, aloneor in combination with other flame retardants, are particularly usefulin the compositions disclosed herein.

The polycarbonate compositions may optionally comprise anti-drip agents.The anti-drip agent may be a fibril forming fluoropolymer such aspolytetrafluoroethylene (PTFE). The anti-drip agent can be encapsulatedby a rigid copolymer as described above, for examplestyrene-acrylonitrile copolymer (SAN). PTFE encapsulated in SAN is knownas TSAN. Encapsulated fluoropolymers can be made by polymerizing theencapsulating polymer in the presence of the fluoropolymer, for examplean aqueous dispersion. TSAN can provide significant advantages overPTFE, in that TSAN can be more readily dispersed in the composition. Anexemplary TSAN can comprise 50 wt % PTFE and 50 wt % SAN, based on thetotal weight of the encapsulated fluoropolymer. The SAN can comprise,for example, 75 wt % styrene and 25 wt % acrylonitrile based on thetotal weight of the copolymer. Alternatively, the fluoropolymer can bepre-blended in some manner with a second polymer, such as for, example,an aromatic polycarbonate or SAN to form an agglomerated material foruse as an anti-drip agent. Either method can be used to produce anencapsulated fluoropolymer.

The polycarbonate compositions can optionally further comprise a fillercomposition. The filler composition is present in an amount of 1 wt % to20 wt % or 1 to 15 wt % based on the total weight of the polycarbonatecomposition. In an embodiment, the filler composition comprises titaniumdioxide.

The polycarbonate compositions have excellent aesthetic properties. Amolded article of the composition with a thickness of 1 mm can have lessthan 10% or less than 5%, measured by HazeGard (ASTM D1003-00). A moldedarticle of the composition with a thickness of 3 mm can have less than50% or less than 10%, measured by HazeGard (ASTM D1003-00).

The polycarbonate compositions can further have good impact properties.The compositions have an Izod notched impact energy of at least 700 J/mmeasured at +23° C. on a sample of 3.2 mm thickness according to ASTMD256-10.

The polycarbonate compositions can have a ductile/brittle transitiontemperature of less than or equal to −10° C. determined in accordancewith ASTM D256-2010 on a molded part having a thickness of 3.2 mm.

The polycarbonate compositions can have good chemical resistance. Thecompositions have a tensile yield strength retention of 80% and higherafter exposure of an ISO tensile bar for 24 hours to sunscreen under0.5% strain compared to a non-exposed reference tested according to ISO22088-3; and an elongation at break retention of 75% and higher afterexposure of an ISO tensile bar for 24 hours to sunscreen under 0.5%strain compared to a non-exposed reference tested according to ISO22088-3.

The polycarbonate compositions can further have good melt viscosities,which aid processing. The polycarbonate compositions have a melt volumeflow rate (MVR, cubic centimeter per 10 minutes (cc/10 min) of 4 to 30,greater than or equal to 5, greater than or equal to 8, greater than orequal to 10, greater than or equal to 12, greater than or equal to 14,greater than or equal to 16, greater than or equal to 18, or greaterthan or equal to 20, determined in accordance with ASTM D1238 under aload of 1.2 kg at 300° C. The same or similar values can be obtained inarticles having a wide range of thicknesses, for example from 0.1 to 10mm, or 0.5 to 5 mm.

In an embodiment, a polycarbonate composition comprises: a firstpoly(carbonate-siloxane) copolymer comprising carbonate units andsiloxane units, wherein less than 0.5 mol % of the siloxane units aredirectly coupled to another siloxane unit; the firstpoly(carbonate-siloxane) copolymer comprising siloxane units with anaverage block length of about 10 to about 100, and a siloxane contentfrom 5 wt % to 8 wt % based on the total weight of the firstpoly(carbonate-siloxane) copolymer; a second poly(carbonate-siloxane)copolymer comprising carbonate units and siloxane units, wherein lessthan 0.5 mol % of the siloxane units are directly coupled to anothersiloxane unit; the second poly(carbonate-siloxane) copolymer comprisingsiloxane units with an average block length of 10 to 100, a siloxanecontent from 10 wt % to 30 wt % based on the total weight of the secondpoly(carbonate-siloxane) copolymer, and wherein the weight ratio of thefirst poly(carbonate-siloxane) copolymer to the secondpoly(carbonate-siloxane) copolymer is 2 to 20; and optionally abisphenol polycarbonate different from the firstpoly(carbonate-siloxane) copolymer and the secondpoly(carbonate-siloxane) copolymer; wherein the polycarbonatecomposition has a total siloxane content of 2.5 wt % to 10 wt % based onthe total weight of the composition and a molded part of 1 mm thicknesshas a haze of less than 2% as measured by HazeGard (ASTM D1003-00).

An exemplary polycarbonate composition comprises, based on the totalweight of the composition, 30 wt % to 95 wt % of the firstpoly(carbonate-siloxane) copolymer; 1 wt % to 20 wt % of the secondpoly(carbonate-siloxane) copolymer; and 0 wt % to 69 wt % of thebisphenol polycarbonate comprising a bisphenol A homopolycarbonate.

Another exemplary polycarbonate composition comprises, based on thetotal weight of the composition, 35 wt % to 75 wt % of the firstpoly(carbonate-siloxane) copolymer; 3 wt % to 15 wt % of the secondpoly(carbonate-siloxane) copolymer; and 15 wt. % to 62 wt. % of thebisphenol polycarbonate comprising a bisphenol A homopolycarbonate.

The polycarbonate compositions can be manufactured by various methodsknown in the art. For example, powdered polycarbonate homopolymer,polycarbonate-polysiloxane copolymer and other optional components arefirst blended, optionally with any fillers, in a high speed mixer or byhand mixing. The blend is then fed into the throat of a twin-screwextruder via a hopper. Alternatively, at least one of the components canbe incorporated into the composition by feeding it directly into theextruder at the throat and/or downstream through a sidestuffer, or bybeing compounded into a masterbatch with a desired polymer and fed intothe extruder. The extruder is generally operated at a temperature higherthan that necessary to cause the composition to flow. The extrudate canbe immediately quenched in a water bath and pelletized. The pellets soprepared can be one-fourth inch long or less as desired. Such pelletscan be used for subsequent molding, shaping, or forming.

Shaped, formed, casted, or molded articles comprising the polycarbonatecompositions are also provided. The polycarbonate compositions can bemolded into useful shaped articles by a variety of methods, such asinjection molding, extrusion, rotational molding, blow molding andthermoforming. The article can be a molded article, a thermoformedarticle, an extruded film, an extruded sheet, a honeycomb structure, oneor more layers of a multi-layer article, a substrate for a coatedarticle, and a substrate for a metallized article.

The article is a component of a consumer electronic device selected froma gaming console, a gaming controller, a portable gaming device, acellular telephone, a television, a personal computer, a tabletcomputer, a laptop computer, a personal digital assistant, a portablemedia player, a, a digital camera, a portable music player, anappliance, a power tool, a robot, a toy, a greeting card, a homeentertainment system, and active loudspeaker, or a soundbar.

The article is an electronic housing for an adapter, a cell phone, asmart phone, a GPS device, a laptop computer, a tablet computer, ane-reader, a copier, or a solar apparatus.

The article is an automotive, scooter, and motorcycle exterior andinterior component comprising panels, quarter panels, rocker panels,trim, fenders, battery covers, doors, deck-lids, trunk lids, hoods,bonnets, roofs, bumpers, fascia, grilles, mirror housings, pillarappliqués, cladding, body side moldings, wheel covers, hubcaps, doorhandles, spoilers, window frames, headlamp bezels, headlamps, taillamps, tail lamp housings, tail lamp bezels, license plate enclosures,roof racks, and running boards.

The above described and other features are exemplified by the followingdetailed description and Examples. In the examples, unless otherwisespecified, the percent (%) of the components as well as the percent (%)of siloxane are weight percent based on the sum of the weights of thebisphenol A linear polycarbonate homopolymer and the(polydimethylsiloxane)-bisphenol A polycarbonate copolymer.

EXAMPLES Materials

The polycarbonates and polycarbonate copolymers used in the Examples aredescribed in Table 1.

In Table 1, a reference to D45 means a dimethylsiloxane block having anaverage number of siloxane units of 45+/−5. The “Tube” copolymers weremanufactured using one or more of the tube reactor processes describedin U.S. Patent Application Publication No. 2004/0039145, or the processdescribed in U.S. Pat. No. 6,723,864, or the process described in U.S.Pat. No. 8,466,249. The “Upfront” copolymers were manufactured byintroducing phosgene under interfacial reaction conditions into amixture of bisphenol A and a eugenol terminated polydimethylsiloxane.The EE/EB ratio refers to the molar ratio of the polydimethylsiloxanesubunits directly coupled to another polydimethylsiloxane submit (EE)relative to the polydiorganosiloxane subunits directly coupled to BPAsubunit (EB) for the PDMS-BPA polycarbonate copolymer. The EE/EB ratiowas determined via nuclear magnetic resonance (NMR) spectroscopy.

The weight average molecular weights (Mw) in Table 1 were measured bygel permeation chromatography using polycarbonate standards. The percentof siloxane is weight percent based on the weight of the copolymer.

TABLE 1 Source, Component Chemical Description Vendor PC1 LinearBisphenol A Polycarbonate homopolymer, SABIC produced via interfacialpolymerization, Mw of about 21,800 g/mol as determined by GPC usingpolycarbonate standards, para- cumylphenol (PCP) end-capped PC2 LinearBisphenol A Polycarbonate homopolymer, SABIC produced via interfacialpolymerization, Mw of about 30,500 g/mol as determined by GPC usingpolycarbonate standards, phenol end-capped SiPC3 PDMS(polydimethylsiloxane) - Bisphenol A SABIC Polycarbonate copolymer,produced via interfacial polymerization, 20 wt. % siloxane, average PDMSblock length of 45 units (D45), Mw about 30,000 g/mol as determined byGPC using polycarbonate standards, para-cumylphenol (PCP) end-capped,EE/EB ratio of 38/62 SiPC4 PDMS (polydimethylsiloxane) - Bisphenol ASABIC Polycarbonate copolymer, produced via interfacial polymerization,20 wt. % siloxane, average PDMS block length of 45 units (D45), Mw about30,000 g/mol as determined by GPC using polycarbonate standards,para-cumylphenol (PCP) end-capped, EE/EB ratio of 0/100 SiPC5 PDMS(polydimethylsiloxane) - Bisphenol A SABIC Polycarbonate copolymer,produced via interfacial polymerization, 6 wt. % siloxane, average PDMSblock length of 45 units (D45), Mw about 23,000 g/mol as determined byGPC using polycarbonate standards, para-cumylphenol (PCP) end-capped,EE/EB ratio of 0/100 I-168 Tris(2,4-ditert-butylphenyl)phosphite(Irgafos 168) Ciba

The additive composition that was used in the Examples contains 0.03 to0.06% of I-168 as heat stabilizer.

Extrusion and Molding Conditions.

The compositions were prepared by pre-blending all constituents in adry-blend and tumble mixed for 15 minutes. The pre-blend was feddirectly to a co-rotation twin screw extruder under the conditions shownin Table 2. The extrudate was pelletized and dried in a dehumidifyingdryer at about 120° C. for about 3 hours. To make test specimens, thedried pellets were injection molded in an ENGEL molding machine to formappropriate test samples under the conditions shown in Table 2.

TABLE 2 Compounding Injection Molding Machine: Machine:Werner-Pfleiderer ZSK twin-screw extruder (25 mm) Engel E45, E75, or E90Feed (zone 0) Temperature ° C. 40 Pre-dry Time h 2 Zone 1 Temperature °C. 200 Pre-dry Temperature ° C. 120 Zone 2 Temperature ° C. 250 HopperTemperature ° C. 40 Zone 3 Temperature ° C. 270 Zone 1 Temperature ° C.280 Zones 4-9 Temperature ° C. 285 Zone 2 Temperature ° C. 290 ScrewSpeed rpm 300 Zone 3 Temperature ° C. 300 Throughput kg/h 18-24 NozzleTemperature ° C. 295 Torque % 50-70 Mold Temperature ° C. 90 Vacuum 1bar 0.7 Cycle Time s ±37Testing Methods.

Tensile properties were measured in accordance to ISO 527 at 50 mm/minat room temperature on standard ISO tensile bars.

Notched Izod impact Strength (‘INI’) was determined in accordance withASTM D256-10 under a load of 5 lbf at various temperatures including 23°C., −30° C. or −50° C. All INI determinations were carried out on sampleplaques of 3.2 mm thickness.

Melt volume rate (“MVR”) was determined in accordance with ASTM D1238under a load of 1.2 kg at 300° C.

Haze measurement by HazeGard (ASTM D1003-00) used injected moldedsamples of 1 mm or 3 mm thickness.

Environmental Stress Cracking Resistance (“ESCR”) describes theaccelerated failure of polymeric materials, as a combined effect ofenvironment, temperature, and stress. The failure mainly depends on thecharacteristics of the material, chemical, exposure condition, and themagnitude of the stress. The tests followed ISO 22088-3 standard andused ISO tensile bars under 0.5% or 1% strain for 24 hours at roomtemperature with chemical (BANANABOAT sunscreen) applied on the surface.After 24 hours, the retention of tensile strength and elongation tobreak, measured according to ISO 527, compared to the non-exposedreference.

Examples 1-2 and Comparative Examples 3-6

Exemplary compositions of the present disclosure (E1-2), along withcontrol or comparative compositions (CE3-6) are shown in Tables 3. Theflow, impact, and haze properties were assessed for each sample, and theresults are summarized in Tables 3.

TABLE 3 CE3 CE4 CE5 CE6 E1 E2 PC1 12.5 37.5 68.7 45.0 31.6 8.7 PC2 37.526.4 7.3 SiPC5 75.0 53.6 26.8 35.0 74.0 SiPC4 7.0 14.0 SiPC3 12.5 8.94.5 17.5 Additives 0.03 0.03 0.03 0.03 0.03 0.03 Total 100 100 100 100100 100 Si content 7.0 5.0 2.5 3.5 3.5 7.0 Ratio* 6 6 6 — 5 5 PropertiesMVR (cm³/10 min) 8.4 11.8 18.1 9.7 10.9 8.3 INI @ 23° C. (J/m) 651 750704 837 830 804 Ductility (%) 100 100 100 100 100 100 INI @ −30° C.(J/m) 621 655 615 759 603 597 Ductility (%) 100 100 100 100 100 100 Haze@ 1 mm (%) 13.2 14.8 11.9 67 1.0 0.6 Haze @ 3 mm (%) 94.7 95.6 87.3 1004.7 2.3 *Ratio refers to weight ratio of SiPC5 relative to a differentsecond SiPC

Comparative Example 6 is a blend of polycarbonate and SiPC3. Althoughthe composition has good impact with INI at 23° C. higher than 800 J/m,this composition has poor aesthetics with very high haze values at both1 mm (67%) and at 3 mm (100%). Comparative Examples 3, 4 and 5 showcompositions containing polycarbonate PC1 with a first SiPC (SiPC5) anda second SiPC (SiPC3) having different siloxane loadings (7, 5 and 2.5%respectively). The weight ratios of SiPC5 to SiPC3 in the compositionsof Comparative Examples 3-5 are 6. These compositions have relativelyhigh haze values at both 1 mm (above 10%) and 3 mm (above 85%), butsignificantly improved, especially at 1 mm thickness, compared to CE×8,which only contains SiPC3. SiPC5 acts as a compatibilizer for SiPC3 toimprove compatibility of SiPC3 with PC and to improve the dispersion andparticle size of the siloxane domains in the PC matrix, but a ratio ofSiPC5 to SiPC3 of 6 is not high enough to achieve good aestheticproperties. US 20140357781 discloses that when the ratio of SiPC5 toSiPC3 is greater than 8, aesthetics can be improved.

The compositions of the disclosure in Examples 1 to 2 are based onblends of polycarbonate (PC1 and PC2) with SiPC5 and a different secondSiPC type, namely SiPC4 at SiPC5 to second SiPC type ratio of 5, andsiloxane loadings of 3.5 and 7%. Both SiPC3 and SiPC4 containing 20 wt %siloxane, but are made via a different process, resulting insignificantly different EE/EB ratios. SiPC4 has an EE/EB ratio of 0/100,whereas SiPC3 has an EE/EB ratio of 38/62. These compositions havesimilar flow properties (MVR in range of 8 to 11) as the comparativeexamples CE3 and CE4, and have good impact properties with ductile ASTMINI at −30° C. In addition, the compositions of Examples 1 to 2 have,despite a lower ratio of SiPC5 to second SiPC (SiPC4) of 5, compared tocompositions containing SiPC5 and SiPC3 (CE3, CE4 and CE5 with a ratioof 6), excellent aesthetics with very low haze values below 1% at 1 mmcompared to above 10% for CE3-5. As such, these compositions of Examples1-2 containing novel combinations of two SiPC types with specificcompositions offer a better balance of impact and aesthetics vs blendsof SiPC5 and SiPC3.

The results indicate that replacing SiPC3 in blends containing PC, SiPC5and SiPC3 (20% siloxane, prepared via an upfront process) with SiPCcopolymers with similar siloxane loading as SiPC3 but produced via atubular process (SiPC4) and low EE/EB ratio of 0/100 instead of highEE/EB ratio for SiPC3 (38/62) provides formulations having balancedproperties compared to blends of PC with SiPC5 and SiPC3 at SiPC3/secondSiPC weight ratios of 5 (which is not sufficient for SiPC3 and SiPC5blends to achieve good aesthetics). SiPC4 acts as compatibilizer andfurther improves aesthetics of the composition containing both SiPC5 andSiPC4.

Examples 7-10 and Comparative Examples 11-12

Examples 7-10 illustrate the impact and aesthetic properties ofcompositions containing SiPC5 and a second SiPC namely SiPC4, whereinthe weight ratios of SiPC5 relative to the second SiPC are equal to orgreater than 10, and an optional PC. The second SiPC in ComparativeExample 11 is SiPC3. The results are shown in Table 4.

TABLE 4 CE11 CE12 E7 E8 PC1 3.7 16.6 22.31 PC2 26.76 SiPC5 87.5 83.447.7 93.7 SiPC3 8.7 SiPC4 3.2 6.3 Additives 0.03 0.03 0.03 0.03 Total100 100 100 100 Si content 7.0 5.0 3.5 7.0 Ratio 10 — 15 15 MVR (cm3/10min) 7.8 11.2 11.1 8.4 INI @ 23° C. (J/m) 660 725 840 685 Ductility (%)100 100 100 100 INT @ −30° C. (J/m) 624 594 597 530 Ductility (%) 100100 100 100 Haze @ 1 mm (%) 4.8 0.5 0.6 0.5 Haze @ 3 mm (%) 55.2 1.6 2.01.4

Comparative Example 11 shows that a composition containing polycarbonate(PC1), a first SiPC (SiP5) and a second SiPC (SiPC3) with higher ratiosof SiPC5 to SiPC3 of 10 has improved aesthetics. Compared to theprevious set of comparative examples CE 3-5 in Table 3, the compositionof CE11 has relatively low haze values at 1 mm (<5%) but stillrelatively high haze at 3 mm (above 50%). As such, despite the moreefficient compatibilization by SiPC5 at ratio of 10 compared to a ratioof 6 (CE3 to 5), such compositions do not have aesthetics close toblends of polycarbonate and SiPC5 without SiPC3 (Comparative Example12), which has much better haze with haze values below 1% at 1 mm andbelow 2% at 3 mm.

The compositions of Example 7-8 are based on blends of SiPC5 and adifferent second SiPC type, namely SiPC4, and optionally polycarbonate(PC1 and PC2) at SiPC5 to second SiPC type ratios of 15, and siloxaneloadings of 3.5 or 7. These compositions have similar flow properties(MVR in range of 8 to 11) as the comparative examples CE11 and CE12, andhave good impact properties with ductile ASTM INI at −30° C. Inaddition, all these compositions, have significantly improved aestheticscompared to CE11, with very low haze values below 2% at 1 mm (comparedto 5% for CE11), and below 10% at 3 mm (compared to >50% for CE11). Assuch, these compositions containing novel combinations of two SiPC typeswith specific compositions offer better balance of impact and aestheticsvs blends of SiPC5 and SiPC3, and approach the excellent aestheticproperties of compositions containing only SiPC5 and PC (CE12).

The formulations of Examples 1-2 (at SiPC5 to second SiPC ratios of 5)offer better aesthetics compared to CE3-5 (SiPC5/SiPC3 blends at a ratioof 6). These aesthetics can be further improved by increasing the ratioof SiPC5 to second SiPC to a value above 10. In this case aestheticsclose to those of CE 12 are obtained.

The advantage of using SiPC5/SiPC4 blends with PC like Examples 7-8 overblends of PC with only SiPC5 (CE×12) becomes clear when evaluatingchemical resistance of the samples according to the ESCR method asdescribed herein. The results of ESCR testing on Examples 7-10 and CE×12are shown in Table 5. Blends of PC with only SiPC5 (CE×12) haverelatively poor chemical resistance to sunscreen and have <60% retentionof tensile strength (TS %) and elongation to break (NS@B %) afterexposure to sunscreen for 1 day under 0.5% strain. Blends of PC withSiPC5 and SiPC4 (E8, E9 and E10) offer better chemical resistance thanblends with only SiPC5 (CE×12), and have good retention of tensilestrength (TS %) (>100%) and elongation to break (NS@B %) (>65%) afterexposure to sunscreen for 1 day under 0.5% strain. Hence, the additionof a second SiPC component to blends of PC and SiPC5 offers an optimizedbalance of chemical resistance and aesthetics in PC/SiPC blends.

TABLE 5 CE12 E7 E8 E9 E10 PC1 16.6 22.31 PC2 26.76 SiPC5 83.4 47.7 93.790 82.5 SiPC3 SiPC4 3.2 6.3 10 17.5 Additives 0.03 0.03 0.03 0.03 0.03Total 100 100 100 100 100 Si content 5.0 3.5 7.0 7.4 8.5 Ratio — 15 15 94.7 MVR (cm3/10 min) 11.2 11.1 8.4 6 5 Bananaboat 0.5% - 60 N/D 101 101101 1 Day - TS% Bananaboat 0.5% - 57 N/D 78 78 65 1 Day - NS@B%

Further included in this disclosure are the following specificembodiments, which do not necessarily limit the claims.

Embodiment 1

A polycarbonate composition comprising:

a first poly(carbonate-siloxane) copolymer comprising carbonate unitsand siloxane units, wherein less than 0.5 mol % of the siloxane unitsare directly coupled to another siloxane unit;

the first poly(carbonate-siloxane) copolymer comprising

siloxane units with an average block length of about 10 to about 100,and

a siloxane content from 5 wt % to 8 wt % based on the total weight ofthe first poly(carbonate-siloxane) copolymer;

a second poly(carbonate-siloxane) copolymer comprising carbonate unitsand siloxane units, wherein less than 0.5 mol % of the siloxane unitsare directly coupled to another siloxane unit;

the second poly(carbonate-siloxane) copolymer comprising

siloxane units with an average block length of 10 to 100,

a siloxane content from 10 wt % to 30 wt % based on the total weight ofthe second poly(carbonate-siloxane) copolymer, and

wherein the weight ratio of the first poly(carbonate-siloxane) copolymerto the second poly(carbonate-siloxane) copolymer is 2 to 20; and

optionally a bisphenol polycarbonate different from the firstpoly(carbonate-siloxane) copolymer and the secondpoly(carbonate-siloxane) copolymer;

wherein the polycarbonate composition has a total siloxane content of2.5 wt % to 10 wt % based on the total weight of the composition and

a molded part of the composition with a 1 mm thickness has a haze ofless than 2% as measured by HazeGard (ASTM D1003-00).

Embodiment 2

The composition of Embodiment 1, wherein a molded article of thecomposition with a 3 mm thickness comprising the composition has a hazeless than 5%, measured by HazeGard (ASTM D1003-00).

Embodiment 3

The composition of Embodiment 1 or Embodiment 2 comprising, based on thetotal weight of the composition,

30 wt % to 95 wt % of the first poly(carbonate-siloxane) copolymer;

1 wt % to 20 wt % of the second poly(carbonate-siloxane) copolymer; and

0 wt % to 69 wt % of the bisphenol polycarbonate comprising a bisphenolA homopolycarbonate.

Embodiment 4

The composition of one or more of Embodiments 1 to Embodiment 3, whereinthe composition comprises, based on the total weight of the composition,

35 wt % to 75 wt % of the first poly(carbonate-siloxane) copolymer;

3 wt % to 15 wt % of the second poly(carbonate-siloxane) copolymer; and

15 wt. % to 62 wt. % of the bisphenol polycarbonate comprising abisphenol A homopolycarbonate.

Embodiment 5

The composition of any one or more of Embodiments 1 to 4, wherein thefirst and second poly(carbonate-siloxane) copolymers independentlycomprise bisphenol carbonate units of the formula

wherein

R^(a) and R^(b) are each independently C₁₋₁₂ alkyl, C₁₋₁₂ alkenyl, C₃₋₈cycloalkyl, or C₁₋₁₂ alkoxy,

p and q are each independently 0 to 4, and

X^(a) is a single bond, —O—, —S—, —S(O)—, —S(O)₂—, —C(O)—, a C₁₋₁₁alkylidene of formula —C(R^(c))(R^(d))— wherein R^(c) and R^(d) are eachindependently hydrogen or C₁₋₁₀ alkyl, or a group of the formula—C(═R^(e))— wherein R^(e) is a divalent C₁₋₁₀ hydrocarbon group; andsiloxane units of the formulas

or a combination comprising at least one of the foregoing, wherein

R is each independently a C₁₋₁₃ monovalent hydrocarbon group,

Ar is each independently a C₆₋₃₀ aromatic group,

R² is each independently a C₂₋₈ alkylene group, and

E has an average value of 10 to 100.

Embodiment 6

The composition of Embodiment 5, wherein the bisphenol carbonate unitsare bisphenol A carbonate units and siloxane units are of the formula

or a combination comprising at least one of the foregoing, wherein E hasan average value of 10 to 100.

Embodiment 7

The composition of any one or more of Embodiments 1 to 6, wherein eachof the first poly(carbonate-siloxane) copolymer and the secondpoly(carbonate-siloxane) copolymer independently comprises siloxaneunits with an average block length of 30 to 60, preferably 30 to 50.

Embodiment 8

The composition of any one or more of Embodiments 1 to 7, wherein theweight ratio of the first poly(carbonate-siloxane) copolymer to thesecond poly(carbonate-siloxane) copolymer is 5 to 15.

Embodiment 9

The composition of Embodiment 1 to 8 wherein the composition has a meltvolume rate (“MVR”), determined in accordance with ASTM D1238 under aload of 1.2 kg at 300° C., higher than 5 and a ductile/brittletransition temperature of less than or equal to −10° C. determined inaccordance with ASTM D256-2010 on a molded part having a thickness of3.2 mm.

Embodiment 10

The composition of Embodiment 9, wherein the composition has a notchedIzod impact of greater than 700 J/m as measured according to ASTMD256-10 at 23° C. on a sample of 3.2 mm thickness.

Embodiment 11

The composition of any one or more of Embodiments 1 to 10 furthercomprising no more than 5 wt. % based on the weight of the compositionof a processing aid, a heat stabilizer, an antioxidant, an ultra violetlight absorber, a colorant, or a combination comprising at least one ofthe foregoing.

Embodiment 12

The composition of Embodiment 11 wherein the colorant compositioncomprises carbon black in an amount of greater than zero and less than1.5 wt. % based on the total weight of the colorant composition.

Embodiment 13

The composition of any one or more of Embodiment 1 to 12, furthercomprising a filler composition.

Embodiment 14

The composition of Embodiment 13, wherein the filler compositioncomprises TiO₂.

Embodiment 15

The composition of Embodiment 13 or 14, wherein the filler compositionis present in an amount from 1 wt % to about 20 wt % based on the totalweight of the composition.

Embodiment 16

The composition of any one or more of Embodiments 1 to 15, wherein amolded article of the composition has reduced aesthetic defectscomprises one or more of the following: haze; black streaking; knitlinevisibility; gate blush; or pearlescence compared to a molded article ofa reference composition comprising the same firstpoly(carbonate-siloxane) copolymer, the same bisphenol polycarbonate,and a second poly(carbonate-siloxane) copolymer comprising carbonateunits and siloxane units, wherein greater than 10 mol % of the siloxaneunits are directly coupled to another siloxane unit.

Embodiment 17

The composition of any one of Embodiments 1 to 16, wherein thecomposition has a tensile yield strength retention of 80% and higherafter exposure of an ISO tensile bar for 24 hours to sunscreen under0.5% strain compared to a non-exposed reference tested according to ISO22088-3; and an elongation at break retention of 60% and higher afterexposure of an ISO tensile bar for 24 hours to sunscreen under 0.5%strain compared to a non-exposed reference tested according to ISO22088-3.

Embodiment 18

The composition of any one or more of Embodiments 1 to Embodiment 17further comprising a colorant composition, wherein a molded samplehaving a thickness of 1 mm formed from the composition has an average L*value of 29 or less as measure by the CIE Lab method, 10 degreeobserver, D65 illuminant, specular component included, measured inreflectance mode.

Embodiment 19

The composition of any one or more of Embodiments 1 to 18, furthercomprising a flame retardant, an anti-drip agent or a combinationcomprising at least one of the foregoing, wherein optionally the flameretardant comprises an alkali metal salt of a perfluorinated C₁-C₁₆alkyl sulfonate, an inorganic acid complex salt.

Embodiment 20

An article selected from a molded article, a thermoformed article, anextruded film, an extruded sheet, a honeycomb structure, one or morelayers of a multi-layer article, a substrate for a coated article, and asubstrate for a metallized article made from the composition of any oneor more of Embodiments 1 to 19, optionally

the article is a component of a consumer electronic device selected froma gaming console, a gaming controller, a portable gaming device, acellular telephone, a television, a personal computer, a tabletcomputer, a laptop computer, a personal digital assistant, a portablemedia player, a, a digital camera, a portable music player, anappliance, a power tool, a robot, a toy, a greeting card, a homeentertainment system, and active loudspeaker, or a soundbar; or thearticle is an electronic housing for an adapter, a cell phone, a smartphone, a GPS device, a laptop computer, a tablet computer, an e-reader,a copier, or a solar apparatus,

or the article is an electrical junction box, an electrical connector,an electrical vehicle charger, an outdoor electrical enclosure, a smartmeter enclosure, a smart grid power node, a photovoltaic frame, aminiature circuit breaker,

or the article is an automotive, scooter, and motorcycle exterior andinterior component comprising panels, quarter panels, rocker panels,trim, fenders, battery covers, doors, deck-lids, trunk lids, hoods,bonnets, roofs, bumpers, fascia, grilles, mirror housings, pillarappliqués, cladding, body side moldings, wheel covers, hubcaps, doorhandles, spoilers, window frames, headlamp bezels, headlamps, taillamps, tail lamp housings, tail lamp bezels, license plate enclosures,roof racks, and running boards.

The singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise. “Or” means “and/or” unlessclearly indicated otherwise by context. Unless defined otherwise,technical and scientific terms used herein have the same meaning as iscommonly understood by one of skill in the art to which this inventionbelongs. A “combination” is inclusive of blends, mixtures, alloys,reaction products, and the like.

As used herein, the term “hydrocarbyl” and “hydrocarbon” refers broadlyto a substituent comprising carbon and hydrogen, optionally with 1 to 3heteroatoms, for example, oxygen, nitrogen, halogen, silicon, sulfur, ora combination thereof; “alkyl” refers to a straight or branched chain,saturated monovalent hydrocarbon group; “alkylene” refers to a straightor branched chain, saturated, divalent hydrocarbon group; “alkylidene”refers to a straight or branched chain, saturated divalent hydrocarbongroup, with both valences on a single common carbon atom; “alkenyl”refers to a straight or branched chain monovalent hydrocarbon grouphaving at least two carbons joined by a carbon-carbon double bond;“cycloalkyl” refers to a non-aromatic monovalent monocyclic ormulticyclic hydrocarbon group having at least three carbon atoms,“cycloalkenyl” refers to a non-aromatic cyclic divalent hydrocarbongroup having at least three carbon atoms, with at least one degree ofunsaturation; “aryl” refers to an aromatic monovalent group containingonly carbon in the aromatic ring or rings; “arylene” refers to anaromatic divalent group containing only carbon in the aromatic ring orrings; “alkylaryl” refers to an aryl group that has been substitutedwith an alkyl group as defined above, with 4-methylphenyl being anexemplary alkylaryl group; “arylalkyl” refers to an alkyl group that hasbeen substituted with an aryl group as defined above, with benzyl beingan exemplary arylalkyl group; “alkoxy” refers to an alkyl group asdefined above with the indicated number of carbon atoms attached throughan oxygen bridge (—O—); and “aryloxy” refers to an aryl group as definedabove with the indicated number of carbon atoms attached through anoxygen bridge (—O—).

Unless otherwise indicated, each of the foregoing groups can beunsubstituted or substituted, provided that the substitution does notsignificantly adversely affect synthesis, stability, or use of thecompound. The term “substituted” as used herein means that at least onehydrogen on the designated atom or group is replaced with another group,provided that the designated atom's normal valence is not exceeded. Whenthe substituent is oxo (i.e., ═O), then two hydrogens on the atom arereplaced. Combinations of substituents and/or variables are permissibleprovided that the substitutions do not significantly adversely affectsynthesis or use of the compound. Exemplary groups that can be presenton a “substituted” position include, but are not limited to, cyano;hydroxyl; nitro; azido; alkanoyl (such as a C₂₋₆ alkanoyl group such asacyl); carboxamido; C₁₋₆ or C₁₋₃ alkyl, cycloalkyl, alkenyl, and alkynyl(including groups having at least one unsaturated linkages and from 2 to8, or 2 to 6 carbon atoms); C₁₋₆ or C₁₋₃ alkoxys; C₆₋₁₀ aryloxy such asphenoxy; C₁₋₆ alkylthio; C₁₋₆ or C₁₋₃ alkylsulfinyl; C₁₋₆ or C₁₋₃alkylsulfonyl; aminodi(C₁₋₆ or C₁₋₃)alkyl; C₆₋₁₂ aryl having at leastone aromatic rings (e.g., phenyl, biphenyl, naphthyl, or the like, eachring either substituted or unsubstituted aromatic); C₇₋₁₉ arylalkylhaving 1 to 3 separate or fused rings and from 6 to 18 ring carbonatoms; or arylalkoxy having 1 to 3 separate or fused rings and from 6 to18 ring carbon atoms, with benzyloxy being an exemplary arylalkoxy.

All cited patents, patent applications, and other references areincorporated herein by reference in their entirety. However, if a termin the present application contradicts or conflicts with a term in theincorporated reference, the term from the present application takesprecedence over the conflicting term from the incorporated reference.

While typical embodiments have been set forth for the purpose ofillustration, the foregoing descriptions should not be deemed to be alimitation on the scope herein. Accordingly, various modifications,adaptations, and alternatives can occur to one skilled in the artwithout departing from the spirit and scope herein.

What is claimed is:
 1. A polycarbonate composition comprising: a firstpoly(carbonate-siloxane) copolymer comprising carbonate units andsiloxane units, wherein less than 0.5 mol % of the siloxane units aredirectly coupled to another siloxane unit; the firstpoly(carbonate-siloxane) copolymer comprising siloxane units with anaverage block length of about 10 to about 100, and a siloxane contentfrom 5 wt % to 8 wt % based on the total weight of the firstpoly(carbonate-siloxane) copolymer; a second poly(carbonate-siloxane)copolymer comprising carbonate units and siloxane units, wherein lessthan 0.5 mol % of the siloxane units are directly coupled to anothersiloxane unit; the second poly(carbonate-siloxane) copolymer comprisingsiloxane units with an average block length of 10 to 100, a siloxanecontent from 10 wt % to 30 wt % based on the total weight of the secondpoly(carbonate-siloxane) copolymer, and wherein the weight ratio of thefirst poly(carbonate-siloxane) copolymer to the secondpoly(carbonate-siloxane) copolymer is 2 to 20; and optionally abisphenol polycarbonate different from the firstpoly(carbonate-siloxane) copolymer and the secondpoly(carbonate-siloxane) copolymer; wherein the polycarbonatecomposition has a total siloxane content of 2.5 wt % to 10 wt % based onthe total weight of the composition and a molded part of the compositionwith a 1 mm thickness has a haze of less than 2% as measured by HazeGard(ASTM D1003-00).
 2. The composition of claim 1, wherein a molded articleof the composition with a 3 mm thickness comprising the composition hasa haze less than 5%, measured by HazeGard (ASTM D1003-00).
 3. Thecomposition of claim 1 comprising, based on the total weight of thecomposition, 30 wt % to 95 wt % of the first poly(carbonate-siloxane)copolymer; 1 wt % to 20 wt % of the second poly(carbonate-siloxane)copolymer; and 0 wt % to 69 wt % of the bisphenol polycarbonatecomprising a bisphenol A homopolycarbonate.
 4. The composition of claim1, wherein the composition comprises, based on the total weight of thecomposition, 35 wt % to 75 wt % of the first poly(carbonate-siloxane)copolymer; 3 wt % to 15 wt % of the second poly(carbonate-siloxane)copolymer; and 15 wt. % to 62 wt. % of the bisphenol polycarbonatecomprising a bisphenol A homopolycarbonate.
 5. The composition of claim1, wherein the first and second poly(carbonate-siloxane) copolymersindependently comprise bisphenol carbonate units of the formula

wherein R^(a) and R^(b) are each independently C₁₋₁₂ alkyl, C₁₋₁₂alkenyl, C₃₋₈ cycloalkyl, or C₁₋₁₂ alkoxy, p and q are eachindependently 0 to 4, and X^(a) is a single bond, —O—, —S—, —S(O)—,—S(O)₂—, —C(O)—, a C₁₋₁₁ alkylidene of formula —C(R^(c))(R^(d))— whereinR^(c) and R^(d) are each independently hydrogen or C₁₋₁₀ alkyl, or agroup of the formula —C(═R^(e))— wherein R^(e) is a divalent C₁₋₁₀hydrocarbon group; and siloxane units of the formulas

or a combination comprising at least one of the foregoing, wherein R iseach independently a C₁₋₁₃ monovalent hydrocarbon group, Ar is eachindependently a C₆₋₃₀ aromatic group, R² is each independently a C₂₋₈alkylene group, and E has an average value of 10 to
 100. 6. Thecomposition of claim 5, wherein the bisphenol carbonate units arebisphenol A carbonate units and siloxane units are of the formula

or a combination comprising at least one of the foregoing, wherein E hasan average value of 10 to
 100. 7. The composition of claim 1, whereineach of the first poly(carbonate-siloxane) copolymer and the secondpoly(carbonate-siloxane) copolymer independently comprises siloxaneunits with an average block length of 30 to
 60. 8. The composition ofclaim 1, wherein the weight ratio of the first poly(carbonate-siloxane)copolymer to the second poly(carbonate-siloxane) copolymer is 5 to 15.9. The composition of claim 1 wherein the composition has a melt volumerate (“MVR”), determined in accordance with ASTM D1238 under a load of1.2 kg at 300° C., higher than 5 and a ductile/brittle transitiontemperature of less than or equal to −10° C. determined in accordancewith ASTM D256-2010 on a molded part having a thickness of 3.2 mm. 10.The composition of claim 9, wherein the composition has a notched Izodimpact of greater than 700 J/m as measured according to ASTM D256-10 at23° C. on a sample of 3.2 mm thickness.
 11. The composition of claim 1further comprising no more than 5 wt. % based on the weight of thecomposition of a processing aid, a heat stabilizer, an antioxidant, anultra violet light absorber, a colorant, or a combination comprising atleast one of the foregoing.
 12. The composition of claim 11 wherein thecolorant composition comprises carbon black in an amount of greater thanzero and less than 1.5 wt. % based on the total weight of the colorantcomposition.
 13. The composition of claim 1, further comprising a fillercomposition.
 14. The composition of claim 13, wherein the fillercomposition comprises TiO₂.
 15. The composition of claim 13, wherein thefiller composition is present in an amount from 1 wt % to about 20 wt %based on the total weight of the composition.
 16. The composition ofclaim 1, wherein a molded article of the composition has reducedaesthetic defects comprises one or more of the following: haze; blackstreaking; knitline visibility; gate blush; or pearlescence compared toa molded article of a reference composition comprising the same firstpoly(carbonate-siloxane) copolymer, the same bisphenol polycarbonate,and a second poly(carbonate-siloxane) copolymer comprising carbonateunits and siloxane units, wherein greater than 10 mol % of the siloxaneunits are directly coupled to another siloxane unit.
 17. The compositionof claim 1, wherein the composition has a tensile yield strengthretention of 80% and higher after exposure of an ISO tensile bar for 24hours to sunscreen under 0.5% strain compared to a non-exposed referencetested according to ISO 22088-3; and an elongation at break retention of60% and higher after exposure of an ISO tensile bar for 24 hours tosunscreen under 0.5% strain compared to a non-exposed reference testedaccording to ISO 22088-3.
 18. The composition of claim 1 furthercomprising a colorant composition, wherein a molded sample having athickness of 1 mm formed from the composition has an average L* value of29 or less as measure by the CIE Lab method, 10 degree observer, D65illuminant, specular component included, measured in reflectance mode.19. The composition of claim 1, further comprising a flame retardant, ananti-drip agent or a combination comprising at least one of theforegoing, wherein optionally the flame retardant comprises an alkalimetal salt of a perfluorinated C₁-C₁₆ alkyl sulfonate, an inorganic acidcomplex salt.
 20. An article selected from a molded article, athermoformed article, an extruded film, an extruded sheet, a honeycombstructure, one or more layers of a multi-layer article, a substrate fora coated article, and a substrate for a metallized article made from thecomposition of claim 1, optionally the article is a component of aconsumer electronic device selected from a gaming console, a gamingcontroller, a portable gaming device, a cellular telephone, atelevision, a personal computer, a tablet computer, a laptop computer, apersonal digital assistant, a portable media player, a, a digitalcamera, a portable music player, an appliance, a power tool, a robot, atoy, a greeting card, a home entertainment system, and activeloudspeaker, or a soundbar; or the article is an electronic housing foran adapter, a cell phone, a smart phone, a GPS device, a laptopcomputer, a tablet computer, an e-reader, a copier, or a solarapparatus, or the article is an electrical junction box, an electricalconnector, an electrical vehicle charger, an outdoor electricalenclosure, a smart meter enclosure, a smart grid power node, aphotovoltaic frame, a miniature circuit breaker, or the article is anautomotive, scooter, and motorcycle exterior and interior componentcomprising panels, quarter panels, rocker panels, trim, fenders, batterycovers, doors, deck-lids, trunk lids, hoods, bonnets, roofs, bumpers,fascia, grilles, mirror housings, pillar appliqués, cladding, body sidemoldings, wheel covers, hubcaps, door handles, spoilers, window frames,headlamp bezels, headlamps, tail lamps, tail lamp housings, tail lampbezels, license plate enclosures, roof racks, and running boards.